1. Field of the Invention
The present invention relates to a static charge eliminator and an image forming system.
2. Description of the Related Art
Conventionally, there has been an electrophotographic image forming apparatus. Generally, this image forming apparatus equally charges and initializes a photosensitive drum in a developing device, forms a latent image on the photosensitive drum by optical writing, develops this latent image to a toner image, directly or indirectly transfers the toner image to a print target medium, and causes a fixing device to fix the toner image.
Here, electric charge is easily accumulated in the print target medium to be conveyed within the image forming apparatus. If the electric charge is only eliminated via a shaft in a roller used for the conveyance, the electric charge cannot be completely eliminated. Thus, static charge elimination members such as static charge elimination brushes are arranged in several areas on the conveyance path of the print target medium in the image forming apparatus.
The print target medium is charged with the largest amount of electric charge when it separates from a conveyance belt or a conveyance roller. Accordingly, a static charge elimination member may often be arranged just behind the conveyance roller. That is, the static charge elimination member is arranged with high frequency just behind an ejection (conveyance) roller into which the print target medium is finally ejected, as disclosed in Japanese Patent Application Laid-Open (Kokai) Publication No. 02-023384.
In the above-described image forming apparatus, a long sheet, which is not cut, may be used as the print target medium. When the long sheet after printing is to be wound, the ejection direction of the ejected long sheet is changed by a reversing unit installed on the lower flow side in the sheet ejection of the image forming apparatus, a tip end portion of the ejected long sheet is then stuck once to a winding core (paper core) mounted on a winding shaft in a winding device, and then a winding operation is started.
However, when the ejected long sheet is to be wound by the winding device, an angle at which the long sheet is conveyed greatly changes depending on the length (the winding diameter) of the long sheet wound around the winding shaft. In such a case, the static charge elimination member fixedly arranged cannot follow the movement (the conveyance angle) of the wound long sheet. Therefore, static charge cannot be reliably eliminated.